Search form

Why Can't Americans Get Their Heads Around Roundabouts?

They're safer, faster, require less fuel use and enhance public space. So why do Americans tend to reject proposals for roundabouts?

Americans tend to reject roundabouts for a number of reasons, including being unaccustomed to predicting other drivers' behaviors and a preference for traffic signals.

But Tom Vanderbilt argues that Americans need to get over their bias for roundabouts, and lays out out several reasons why they're far superior to regular binary intersections.

"There are few silver bullets when it comes to traffic, and roundabouts will not work everywhere. (Some intersections are already too busy to consider switching to the roundabout model.) Like anything, they can be poorly designed: You don't want them to look as if someone simply traced 'a circle around a coffee can' on a piece of paper, as one engineer has put it. Yes, there will perhaps have to be some minor educational outreach-one Indiana town is weighing spending $24,000 to do just that-but a larger question here is whether people who cannot manage to merge at low speed into a counter-clockwise circle and, yes, perhaps even change lanes in that circle, before finding the correct exit should actually be holding licenses that enable them to operate heavy machinery in the first place."

Comments

Comments

a larger question indeed

"...but a larger question here is whether people who cannot manage to merge at low speed into a counter-clockwise circle and, yes, perhaps even change lanes in that circle, before finding the correct exit should actually be holding licenses that enable them to operate heavy machinery in the first place."

Indeed. That is an incredibly valid question, and I know the answer.

No.

Roundabouts In Davis, California

We have a number of roundabouts in Davis. The problem with them is that they are so small that it is nearly impossible to tell who has priority. The reality is that the dominant through-street takes priority by sheer volume of traffic and speed of traffic. Davis is home to many bicycles, and roundabouts are decidedly un-friendly to bikes. The only practical way to navigate them on a bike is to force yourself into the middle of the drive lane (in with the cars) and enter the roundabout as if you were a car. There is no safe "lane" around the outside. You can imagine how a parent might feel about their 10 year old riding to school in 8:00 a.m. traffic.

I am familiar with large roundabouts on the East Coast and the dynamics of use are completely different because each car actually spends some time in the circle and because the roads entering the circle are separated by some length of the circular drive so that it is clear who is in the circle as you approach. Of course in the East, you do have to be a more aggressive driver.

Davis' early roundabouts were retrofitted into existing intersections - therefore the cramped size. But new ones built since, are not much larger. The pressures of land cost force this size constraint now. An interesting driver of roundabouts is the cost difference between this kind of intersection and a signalized one - small roundabouts are much cheaper - of course if they are made large enough to work well, the cost savings is lost to the relationship between land costs vs. signal costs.

Paul Deering
Deering Design

Making Round-Abouts Work For Bikes

"The only practical way to navigate them on a bike is to force yourself into the middle of the drive lane (in with the cars) and enter the roundabout as if you were a car. There is no safe "lane" around the outside."

We have similar roundabouts in Berkeley, creating the same problem for bikes.

I think there is a way to make them work for bikes. They need signage telling cars to slow to 15 mph and share the lane with bikes. Ideally, there should also be speed humps forcing drivers to slow to 15 mph as they approach the roundabouts.

My take is that drivers at the roundabouts are just oblivious to the fact that it is dangerous to go around them with a bike right next to you, because you are swerving into the bike. They just need to be reminded that they should merge and share the lane with bikes at the roundabouts.